Flexible robotic actuators

ABSTRACT

Some embodiments of the disclosed subject matter includes a laminated robotic actuator. The laminated robotic actuator includes a strain-limiting layer comprising a flexible, non-extensible material in the form of a sheet or thin film, a flexible inflatable layer in the form of a thin film or sheet in facing relationship with the strain-limiting layer, wherein the inflatable layer is selectively adhered to the strain-limiting layer, and wherein a portion of an un-adhered region between the strain-limiting layer and the inflatable layer defines a pressurizable channel, and at least one fluid inlet in fluid communication with the pressurizable channel. The first flexible non-extensible material has a stiffness that is greater than the stiffness of the second flexible elastomeric material and the flexible elastomer is non-extensible under actuation conditions.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of the earlier filing date of the PCTApplication No. PCT/US2013/022593, entitled “Flexible RoboticActuators,” filed on Jan. 22, 2013, which claims the benefit of the U.S.Provisional Patent Application No. 61/588,596, entitled “FlexibleRobotic Actuators,” filed on Jan. 19, 2012. Each of the PCT Applicationand the U.S. Provisional Patent Application are hereby incorporated byreference herein in their entirety.

All patents, patent applications and publications cited herein arehereby incorporated by reference in their entirety in order to morefully describe the state of the art as known to those skilled therein asof the date of the invention described herein.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

The present invention was made with United States government supportunder Grant No. W911NF-11-1-0094 awarded by Defense Advanced ResearchProjects Agency (DARPA). The United States government has rights in thisinvention.

BACKGROUND

This technology relates generally to flexible actuators. In particular,this invention relates to substantially thin robotic manipulators.

Most robots are constructed using so-called “hard” body plans; that is,a rigid (usually metal) skeleton, electrical or hydraulic actuation,electromechanical control, sensing, and feedback. These robots are verysuccessful at the tasks for which they were designed (e.g., heavymanufacturing in controlled environments) but have severe limitationswhen faced with more demanding tasks (for example, stable motility indemanding environments): tracks and wheels perform less well than legsand hooves.

Evolution has selected a wide range of body plans for mobile organisms.Many approaches to robots that resemble animals with skeletons are beingactively developed: “Big Dog” is an example. A second class ofrobot—those based on animals without skeletons—are much less explored,for a number of reasons: i) there is a supposition that “marine-like”organisms (squid) will not operate without the buoyant support of water;ii) the materials and components necessary to make these systems are notavailable; iii) the major types of actuation used in them (for example,hydrostats) are virtually unused in conventional robotics. These systemsare intrinsically very different in their capabilities and potentialuses than hard-bodied systems. While they will (at least early in theirdevelopment) be slower than hard-bodied systems, they will also be morestable and better able to move through constrained spaces (cracks,rubble), lighter, and less expensive.

Robots, or robotic actuators, which can be described as “soft” are mosteasily classified by the materials used in their manufacture and theirmethods of actuation. The field of soft robotic actuation began withwork by Kuhn et al in 1950. Their work focused on the reversible changein the coiling and uncoiling of a polymeric material dependant on the pHof the surrounding medium. They used this to successfully raise andlower a weight, thus showing proof of principle for the use of softmaterials in robotic actuation. Hamlen et al expanded upon this idea in1965 and showed that polymeric materials can be made to contractelectrolytically. These two developments set the scene for future workusing the swelling of polymeric gels and electronic control ofdielectric-based actuators. Otake et al have demonstrated the use ofelectro-active polymers in the manufacture of starfish-shaped roboticactuators. Pneumatically-driven soft actuators based on pressurizationof sealed chambers fabricated from extensible polymers were firstreported by Suzumori et al in 1991. This type of actuation has been usedon the millimeter scale to fabricate grippers, tentacles, and otherrelated devices including pneumatic balloon actuators.

Pneumatic soft robotic actuators can be manufactured using inextensiblematerials, which rely on architectures such as bellows. McKibbenactuators, also known as pneumatic artificial muscles (PMAs), rely onthe inflation of a bladder constrained within a woven sheath which isinextensible in the axis of actuation. The resultant deformation leadsto radial expansion and axial contraction; the force that can be appliedis proportional to the applied pressure. Related actuators are calledpleated pneumatic artificial muscles.

There are “soft” robotic actuators such as shape memory alloys whichhave been used by Sugiyama et al both as the actuation method and as themain structural component in robots which can both crawl and jump.Another approach, which can be described as “soft” uses a combination oftraditional robotic elements (an electric motor) and soft polymericlinkages based on Shape Deposition Manufacturing (SDM). This techniqueis a combination of 3D printing and milling. An example of a compositeof traditional robotics with soft elements has been used with greatsuccess in developing robotic grippers comprising soft fingers toimprove the speed and efficiency of soft fruit packing in New Zealand.

SUMMARY

Flexible robotic actuators are described. These and other aspects andembodiments of the disclosure are illustrated and described below.

The disclosed subject matter includes a laminated robotic actuator. Thelaminated robotic actuator can include a strain-limiting layercomprising a flexible, non-extensible material in the form of a sheet orthin film, a flexible inflatable layer in the form of a thin film orsheet in facing relationship with the strain-limiting layer, wherein theinflatable layer is selectively adhered to the strain-limiting layer,and wherein a portion of an un-adhered region between thestrain-limiting layer and the inflatable layer defines a pressurizablechannel, and at least one fluid inlet in fluid communication with thepressurizable channel. The first flexible non-extensible material has astiffness that is greater than the stiffness of the second flexibleelastomeric material and the flexible elastomer is non-extensible underactuation conditions.

In any of the embodiments described herein, the laminated roboticactuator can include an adhesive layer disposed between thestrain-limiting layer and the inflatable layer, wherein the adhesivelayer is shaped to selectively adhere the inflatable layer to thestrain-limiting layer to define the channel.

In any of the embodiments described herein, one of the strain-limitinglayer and the inflatable layer is coated with an adhesive, and thelaminated robotic actuator further includes a masking layer disposedbetween the strain-limiting layer and the inflatable layer, wherein themasking layer defines a shape of the un-adhered region between thestrain-limiting layer and the inflatable layer.

In any of the embodiments described herein, the strain-limiting layerincludes the adhesive coating.

In any of the embodiments described herein, the channel includes aplurality of interconnected chambers configured to provide a twistingmotion of the flexible robotic actuator upon pressurization of thechannel via the fluid inlet.

In any of the embodiments described herein, the channel includes aplurality of interconnected chambers configured to provide a bendingmotion of the flexible robotic actuator upon pressurization of thechannel via the fluid inlet.

In any of the embodiments described herein, a stiffness of thestrain-limiting layer is configured to determine a physical strengthassociated with the flexible robotic actuator upon pressurization of thechannel via the fluid inlet.

In any of the embodiments described herein, the channel includes aplurality of interconnected chambers configured to provide two differentmotions of the flexible robotic actuator upon pressurization of thechannel via the fluid inlet.

In any of the embodiments described herein, the actuator furtherincludes a reinforcing structure for providing additional physicalsupport to the flexible robotic actuator.

In any of the embodiments described herein, the channel includes aplurality of sub-channels that are independently coupled to the at leastone fluid inlet, thereby enabling independent pressurization of thesub-channels.

In any of the embodiments described herein, the channel includes aplurality of interconnected chambers arranged along a curved centralflow conduit.

The disclosed subject matter also includes a twisting actuatorcomprising a flexible robotic actuator in accordance with any of theembodiments described herein. The pressurizable channel includes acentral flow conduit and a plurality of slanted branches, and theslanted branches are at an acute angle with respect to a central axis ofthe actuator to determine a twisting motion of the actuator.

In any of the embodiments described herein, the central axis of thetwisting actuator is aligned with the central flow conduit.

The disclosed subject matter also includes a lifting robot. The liftingrobot includes a flexible robotic actuator in accordance with any of theembodiments described herein. The pressurizable channel includes radialchannels arranged in a concentric manner about a central point of theflexible robotic actuator, and connecting channels perpendicular to theradial channels, wherein the radial channels are configured to deflectaway from a surface of the strain-limiting layer upon pressurization.

The disclosed subject matter also includes a robot comprising aplurality of actuatable arms in accordance with any of the embodimentsdescribed herein, wherein each of the plurality of actuatable armsincludes a flexible robotic actuator in accordance with any of theembodiments described herein.

In any of the embodiments described herein, the robot includes 2, 3, 4,5, 6, 7, 8 or more actuatable arms.

In any of the embodiments described herein, one or more of the pluralityof actuatable arms is configured to be actuated independently.

The disclosed subject matter also includes a gripping device comprisinga plurality of actuatable arms. Each of the plurality of actuatable armsincludes a flexible robotic actuator in accordance with any of theembodiments described herein, wherein the plurality of actuatable armsare configured to bend from a first resting position to a secondactuated position upon pressurization.

In any of the embodiments described herein, the gripping device includes2, 3, 4, 5, 6, 7, 8 or more actuatable arms.

In any of the embodiments described herein, one or more of the pluralityof actuatable arms is configured to be actuated independently.

The disclosed subject matter also includes a method for providing aflexible robotic actuator. The method includes providing astrain-limiting layer having a substantially two-dimensional layer of afirst flexible material, providing an inflatable layer having asubstantially two-dimensional layer of a second flexible material,wherein the second flexible material is non-extensible, and the firstflexible material is stiffer compared to the second flexible material,and determining a shape of a region at which the inflatable layer is tobe adhered to the strain-limiting layer. The method can further includeadhering the inflatable layer to the strain-limiting layer based on theshape of the region, thereby forming a channel for fluid communicationhaving the shape.

In any of the embodiments described herein, the method for providing aflexible robotic actuator can also include providing an adhesive layerbetween the strain-limiting layer and the inflatable layer, wherein theadhesive layer is shaped to selectively adhere the inflatable layer tothe strain-limiting layer to define the channel.

In any of the embodiments described herein, the method for providing aflexible robotic actuator can also include providing a masking layerdisposed between the strain-limiting layer and the inflatable layer,wherein the masking layer defines a shape of the un-adhered regionbetween the strain-limiting layer and the inflatable layer.

The disclosed subject matter includes a method of actuating a laminatedsoft robotic. The method can include providing a laminated soft roboticin accordance with any of the embodiments described herein, andinitiating a series of pressurizations and depressurizations thatactuate the laminated soft robotic to provide a predetermined motion.

In any of the embodiments described herein, the series of pressurizationand depressurizations provide a sequence of two or more predeterminedmotions.

The disclosed subject matter includes a method of gripping. The methodof gripping can include providing a gripping device in accordance withany of the embodiments described herein, and initiating a series ofpressurizations and depressurizations that bring the arms in grippingcontact with a target object.

In any of the embodiments described herein, the method of gripping canalso include initiating a series pressurizations and depressurizationsto perform a walking motion.

In any of the embodiments described herein, the pressure of the fluidapplied to the channel via the fluid inlet is selected to provide apredetermined range of a motion.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described with reference to the following figures,which are presented for the purpose of illustration only and are notintended to be limiting.

FIGS. 1A-1B illustrate the principle of pneumatic actuation of aflexible robotic actuator in accordance with some embodiments.

FIGS. 2A-2B illustrates a force diagram and a bending motion of a softrobot having a non-extensible inflatable layer in accordance with someembodiments.

FIGS. 3A-3F illustrate methods for fabricating flexible roboticactuators in accordance with some embodiments.

FIGS. 4A-4E illustrate a flexible, curling actuator in accordance withsome embodiments.

FIGS. 5A-5B illustrate a twisting thin soft robot and its movement inaccordance with some embodiments.

FIGS. 6A-6B illustrate a radially curling thin soft robot and itsmovement in accordance with some embodiments.

FIGS. 7A-7B illustrate a lifting thin robot that is configured to liftan object on the robot in accordance with some embodiments.

FIGS. 8A-8B show a thin actuator with augmented support structures inaccordance with some embodiments.

FIG. 9 illustrates a flexible, undulating actuator capable of anundulating motion in accordance with some embodiments.

FIGS. 10A-10E illustrate a robot having a plurality of thin actuators inaccordance with some embodiments.

FIGS. 11A-11D illustrates a flexible gripper device having three curlingactuators in accordance with some embodiments.

FIG. 12 shows a physical support robot in accordance with someembodiments.

FIG. 13 illustrates an expanding robot that provides an expandingmovement in accordance with some embodiments.

FIG. 14 illustrates a robot having one or more actuators configured toperform a predetermined task in accordance with some embodiments.

FIGS. 15A-15B illustrate an actuator with a plurality of channels inaccordance with some embodiments.

FIGS. 16A-C and 17A-D illustrate a glider with a plurality of thinactuators in accordance with some embodiments.

FIGS. 18A-18D illustrates a paper-based rotor with two flexibleactuators in accordance with some embodiments.

DETAILED DESCRIPTION

Organisms, such as Echinoderms (starfish, sea urchins) and Cnidarians(jellyfish) are ancient and incredibly successful, relatively simpleorganisms capable of movement unheard of in even the most advancedhard-robotic systems. One major reason for the gap between nature andthe state of the art robotic systems is the severe limitation inmaterial selection available for robotics. To bridge this gap betweennature and the state of the art robotic systems, robotic systems haveexploited different materials. For example, a soft robotic system canuse soft materials, such as soft elastomer, to build its structures, asdisclosed in the PCT Patent Application No. PCT/US11/61720, titled “Softrobotic actuators” by Shepherd et al., filed on Nov. 21, 2011, which ishereby incorporated by reference in its entirety.

The present disclosure provides a different approach to bridging the gapbetween nature and the state of the art robotic systems. In particular,disclosed systems and methods provide laminated robotic actuators. Someembodiments of the flexible robotic actuators include a stack ofsubstantially two-dimensional (thin film or sheet) materials that arearranged to form an internal set of pressurizable pathways, which can beconfigured to provide three-dimensional motions. The thin actuators canbe fabricated quickly using cheap materials and cheap processes. Theactuators only require two non-extensible layers having a differingstiffness and (optionally) an adhesive layer that secures the two layerstogether. The strength and the flexibility of the actuator can be easilycontrolled by varying the materials used for the two layers having adifferent stiffness. Furthermore, the arrangement and shape of thepressurizable pathways can be prepared in multiple ways, therebyenabling different motions and applications.

These thin, flexible actuators can provide distinct advantages comparedto other robotic actuators. For example, thin actuators can be easy tostore and transport, and can be configured to maneuver adeptly on flatsurfaces. Furthermore, thin actuators can be lightweight and can enabledevelopments of advanced aerodynamic structures and synthetic marineorganisms. In addition, thin actuators can be configured to operate innarrow spaces unlike other robotic systems, thereby providing roboticsupport in “search and rescue missions”. The thin actuators can beparticularly useful in dealing with crevasses, objects in a packedsetting, or thin objects, obstacles, or cracks in general. For example,it would be challenging for regular soft robotic actuators to grab oneof the eggs in a basket because the space between the eggs is limitedand the actuator would not “fit” into the limited space. In contrast, itwould be easy for thin actuators to grab one of the eggs in a basketsince the thin actuator can fit into the limited space.

The thin, flexible actuators can be useful in a variety of applications.In particular, the thin, flexible actuators can be useful in biomedicalapplications. The thin, flexible actuators can be used as a surgicaltool for delicately manipulating and operating on organs. For example,the flexible actuators can be inserted into narrow incisions and areable to delicately separate organs for a better line of sight. Becauseexisting surgical tools are rigid and hard, if mishandled duringoperation, the existing tools can cut organs or cause unnecessarymedical complications. In contrast, since the thin actuators can be softand flexible, thin actuator based surgical tools are less likely tocause medical complications.

FIG. 1 illustrates a structure of a laminated robotic actuator and itsprinciple of actuation in accordance with some embodiments. The flexiblerobotic actuator 100 can include a plurality of layers stacked on top ofeach other. Each layer can be substantially two-dimensional and is inthe form of a sheet, layer or thin film. A substantially two-dimensionallayer can be characterized as a material having a width, height, andthickness, where the thickness of the material is substantially smallerthan the material's width and height. In some cases, the ratio betweenthe smaller of the width and height of the layer and the thickness ofthe layer can be defined as a form factor. In some embodiments, the formfactor of the substantially two-dimensional layer is at least 5. Inother embodiments, the form factor of the substantially two-dimensionallayer is at least 10. In yet another embodiment, the form factor of thesubstantially two-dimensional layer is at least 20. In yet anotherembodiment, the form factor of the substantially two-dimensional layeris at least 50. In yet another embodiment, the form factor of thesubstantially two-dimensional layer is at least 100. In yet anotherembodiment, the form factor of the substantially two-dimensional layeris at least 200. In yet another embodiment, the form factor of thesubstantially two-dimensional layer is at least 500. In yet anotherembodiment, the form factor of the substantially two-dimensional layeris at least 1000. In yet another embodiment, the form factor of thesubstantially two-dimensional layer is at least 2000. In yet anotherembodiment, the form factor of the substantially two-dimensional layeris at least 5000.

The flexible robotic actuator can include a strain-limiting layer 102and an inflatable layer 104. The strain-limiting layer can limit varioustypes of strains, including a strain resulting from bending, expanding,and/or twisting. Bending, expanding, and twisting strains can applyuniform or anisotropic tensile stress to the strain-limiting layer, andthe strain-limiting layer can resist this tensile stress until its yieldstrength is reached. In some embodiments, the materials for thestrain-limiting layer 102 and the inflatable layer 104 can be selectedto satisfy certain mechanical characteristics, such as the physicalstrength of the actuator upon actuation.

The strain-limiting layer 102, due in part to its thin, 2-dimensionalform factor, is made of a flexible material, e.g., is capable of bendingwithout damage to the layer, but is it relatively stiff, e.g., it isresistant to stretching or expansion. In some cases, the stiffness ofthe strain-limiting layer can determine the physical strength associatedwith the flexible robotic actuator upon actuation.

The strain-limiting layer is made of a stiffer material compared to thatof the inflatable layer 104. For example, the strain-limiting layer 102can include a packaging tape, and a Gorilla Tape®. The strain-limitinglayer 102 can include an extensive range stiff, inextensible materials,including a stiff polymer, such as polyethylene terephthalate (PET), asynthetic fiber, a duct tape, Kevlar©, and a fabric such as paper,cotton, and nylon. Suitable thickness is selected based on the desiredmaterial properties of the material. For example, a thicker sheet willbe stiffer and provide higher bending resistance, requiring a greateractuation force, but greater robot strength. Exemplary thicknesses canrange from tens of micro-meters to a few milli-meters. Such materialsare readily available in sheet and thin film format and can beincorporated into the assembly process without any additional resizingor reprocessing. For example, packaging tapes are commercially availablein thicknesses ranging from 1 mil (ca. 25 μm to 4 mil (ca. 100 μm) inthickness; PET films are commercially sold in thicknesses ranging from10 μm to 1-2 mm.

The inflatable layer 104 is fabricated using a flexible material havinga stiffness that is less than that of the strain-limiting layer 102.Therefore, the inflatable layer 104 bends or deforms more readilycompared to the strain-limiting layer 102. In some cases, the stiffnessof a structure can depend on its material and its shape. Thus, thestiffness of the inflatable layer 104 can be controlled by selecting anadequate material and an adequate shape. In some embodiments, thematerial for the inflatable layer 104 preferably possesses asufficiently high Young's modulus that it does not expand significantlyunder the pressurizing conditions of actuation. Thus, the material forthe inflatable layer 104 bends more readily than the strain-limitingmaterial 102, but does not stretch or expand (as a balloon) under theactuation pressures. In some cases, the actuation pressure can becontrolled so that the inflatable layer 104 does not expand or stretch.For example, the actuation pressure applied to the actuator can bebetween 2 psi and 10 psi. The range of pressure that can be applied tothe actuator while preventing the expansion or stretching of theinflatable layer 104 can depend on the Young's modulus of the materialused for the inflatable layer 104 and the adhesion strength of theadhesive between the inflatable layer 104 and the strain limiting layer102. In some embodiments, the inflatable layer 104 can be formed usingthe same material as the strain-limiting layer 102. In such embodiments,the inflatable layer 104 can be thinner than the strain-limiting layer102 to exhibit less stiffness compared to the strain-limiting layer 102.

Exemplary thicknesses of the inflatable layer 104 can range between tensof micro-meters to hundreds of micro-meters. Exemplary materials includean extensive range of less stiff materials, including a less-stiffpolymers, such as a nitrile, a latex rubber, vinylidene chloride, and alow-density polyethylene. The polymers made from vinylidene chloride caninclude polyvinylidene chloride (PVDC), and Saran® PVDC film and Kevlar©polymer (poly-paraphenylene terephthalamide). Such materials are readilyavailable in sheet and thin film format and can be incorporated into theassembly process without any additional resizing or reprocessing. Forexample, PDVC film is commercially available in thicknesses ranging from1 mil (ca. 25 μm to 4 mil (ca. 100 μm) in thickness; PCV films arecommercially sold in thicknesses ranging from 10 μm to 1-2 mm. In someembodiments, the inflatable layer 104 can be formed using the samematerial as the strain-limiting layer 102. In such embodiments, theinflatable layer 104 can be thinner than the strain-limiting layer 102to exhibit less stiffness compared to the strain-limiting layer 102.

Portions of the strain-limiting layer 102 and the inflatable layer 104can be selectively adhered to each other to form a single laminatestructure having a plurality of layers, as illustrated in FIG. 1A. By“selectively adhered,” it is meant that not all surfaces between the twolayers are glued together. Regions remain unglued and non-adhering tothe facing surface. The unadhered interface between the strain-limitinglayer 102 and the inflatable layer 104 form a channel 106. As discussedin greater detail herein, the unglued, non-adhering regions are selectedto define interconnecting chambers or channels that can be pressurizedusing a pressurizing source. Several ways of adhering the two layers canbe used, as is discussed in greater detail below. The channel 106 can besubstantially hollow and can be substantially contained or surrounded(i.e., compartmentalized) by the adhered interface between thestrain-limiting layer 102 and the inflatable layer 104. Also, thechannel 106 can be coupled to a fluid inlet and can be amenable to fluidcommunication. For example, the channel 106 can be in fluidcommunication with a pressure source via the fluid inlet, therebyreceiving fluid from the pressure source. The pressure source canprovide air, or, more generally, any types of fluid (e.g., water, oil).

A resting state is characterized as a state in which the pressure insidethe channel (“P₁”) is substantially identical to the pressure outsidethe chamber 106, such as the atmospheric pressure (“P_(atm)”). At aresting state, the channel 106 maintains its shape, as illustrated inFIG. 1A in accordance with some embodiments.

A pressurized state is characterized as a state in which the pressureinside the channel is greater than the pressure outside the chamber 106.At a pressurized state, the channel 106 can deform, as illustrated inFIG. 1B in accordance with some embodiments. The deformation of thechannel 106 can depend on the stiffness of the two layers. Because theinflatable layer 104 is less stiff compared to the strain-limiting layer102, the pressurized channel 106 would trigger the inflatable layer 104to deform before the strain-limiting layer 102, thereby providing abending motion.

The direction of the bending motion depends, in part, on the expansionproperty of the inflatable layer 104. For example, if the inflatablelayer 104 is formed using an expansible material, then the inflatablelayer 104 can be deformed and expanded, so that the surface area of theelastomer increases. Upon pressurization, the flexible robotic actuator100 expands, increases its volume, and bends towards the strain-limitinglayer 102, as disclosed in the PCT Patent Application No.PCT/US11/61720, titled “Soft robotic actuators” by Shepherd et al.,filed on Nov. 21, 2011. In other words, the pressurization of theflexible robotic actuator 100 causes the actuator 100 to deflect towardsthe side of the strain-limiting layer 102.

In contrast, where the inflatable layer 104 is formed using a flexible,e.g., bendable, non-expansible material, the inflatable layer 104 can bedeformed, e.g., bended, but cannot be expanded. Upon pressurization, thetension around the perimeter of the channel 106 on the inflatable layer104 pulls the strain-limiting layer 102 at an angle substantially normalto the strain-limiting layer 102, which causes a bending motion towardsthe inflatable layer 104. When pressurized, the “contact angle” betweenthe inflated portion of the inflatable layer 104 and the strain-limitinglayer 102, shown as θ in FIG. 1B, is typically less than 90°, whichindicates that the inflatable layer 104 places a tension on thestrain-limiting layer 102 at the contact point, causing the bendingmotion. In other words, the pressurization of the flexible roboticactuator 100 having a non-extensible inflatable layer would cause theactuator 100 to deflect to the side of the inflatable layer 104.

FIGS. 2A-2B provides a schematic illustration of the forces in playduring pressurization of the laminated soft robotic actuator,demonstrating the bending motion of a soft robot having a non-extensibleinflatable layer in accordance with some embodiments. FIG. 2A shows across-section of a pneumatic channel sealed by a strain-limiting layer102 on one side and an inflatable layer 104 on the other. When thepneumatic channel is pressurized, the pressure would exert a force onthe strain-limiting layer 102 and the inflatable layer 104. The forcesare shown by vectors 202 and 204. The pressure induces the pneumaticchannel to maximize volume while minimizing the surface area. Therefore,the pressure causes the non-extensible inflatable layer 104 to deflectoutward and away from the strain-limiting layer 104. However, thispressure may not be enough to deflect the strain-limiting layer 102outward and away from the inflatable layer 104 since the strain-limitinglayer 102 is stiffer compared to the non-extensible inflatable layer104. Therefore, the net force on the strain-limiting layer 102 would bea downward force, as shown by the large vector 206. This downward forceon the strain-limiting layer 202, along with the effective shortening ofthe inflatable layer 104 through outward deflection, causes a bendingmotion in the direction towards the inflatable layer 104, as illustratedin FIG. 2B.

In some embodiments, operating the flexible robotic actuator using ahigh-pressure source is desirable because the force provided by theflexible actuator can be higher when actuated with a high-power pressuresource. The maximum pressure that can be handled by the channel 106depends on the properties of the strain-limiting layer 102 and theinflatable layer 104 and also on the strength of the attachment betweenthe two layers. Therefore, it is sometimes desirable to secure a strongattachment between the two layers.

FIG. 3 illustrates two methods for fabricating a flexible roboticactuator in accordance with some embodiments. The first method imposes athin layer having an adhesive coating on both sides 302 between thestrain-limiting layer 102 and the inflatable layer 104, as illustratedin FIG. 3A. At a high level, the first method fabricates a flexiblerobotic actuator by adhering strain-limiting layer 102 and inflatablelayer 104 to either side of adhesive layer 302. In some embodiments,adhesive layer 302 can be a double-sided tape such as is commerciallyavailable. Suitable double sided adhesive layers are available from avariety of sources, such as Scotch brand and 3M adhesive tapes. Theadhesive layer 302 can be shaped, e.g., by cutting, punching, embossing,etc., to the desired shape of the channel 106. For example in FIG. 3A, acentral portion 304 is removed from rectangular adhesive layer 302 toform a void space corresponding to channel 106. When the adhesive layeradheres the strain-limiting layer 102 to the inflatable layer 104, itdoes so at every facing position except for the central cutout portion304. Therefore, the strain-limiting layer 102 at the central cutoutportion 304 is not attached to the inflatable layer 104, and thisun-attached interface between the strain-limiting layer 102 and theinflatable layer 104 forms a channel 106.

FIG. 3B shows the top-down view 306 and the front-view 308 of theactuator assembled in accordance with the first method. The adhesivelayer 302 is disposed between the strain-limiting layer 102 and theinflatable layer 104, and the central cutout portion 304 forms thechannel 106. FIG. 3C is a photograph of an actuator 310 fabricated inaccordance with the first method.

The second method for fabricating a flexible robotic actuator uses astrain-limiting layer 102, an inflatable layer 104, and a masking layer312, as illustrated in FIG. 3D. In some embodiments, this method uses astrain-limiting layer 102 with a surface that has thereon an adhesive.The adhesive on the strain-limiting layer 102 can be uniformlydistributed across the surface of the strain-limiting layer 102 or canbe selectively distributed (i.e., patterned) across the surface of thestrain-limiting layer 102. The adhesive can similarly be applied to theinflatable layer in addition to or in place of the strain-limitinglayer.

At a high level, the second method fabricates a flexible roboticactuator by adhering the strain-limiting layer 102 to the inflatablelayer 104 using the adhesive on the top surface of the strain-limitinglayer 102. To form a channel 106, some portions of the strain-limitinglayer 102 can be selectively prevented from adhering to the inflatablelayer 104 using a masking layer 312 (e.g., a patterned spacer). Themasking layer 312 can prevent the physical contact of the two layers,and this un-attached interface between the strain-limiting layer 102 andthe inflatable layer 104 forms a channel 106. In some embodiments, theadhesive can be present on the bottom surface of the inflatable layer104 instead of the top surface of the strain-limiting layer 102; inother embodiments, the adhesive can be present on both the top surfaceof the strain-limiting layer 102 and the bottom surface of theinflatable layer 104. In some cases, the adhesive can include adouble-sided tape or glue. In some embodiments, the strain-limitinglayer 102 can include a single-sided tape that already has adhesiveapplied to it. In other embodiments, the inflatable layer 104 caninclude a single-sided tape that already has adhesive applied to it. Thetape can include a duct tape, a box sealing tape, an electrical tape, afilament tape, a hockey tape, a medical tape, a slug tape, or a surgicaltape.

FIG. 3E shows the top-down view 314 and the front-view 316 of theactuator assembled in accordance with the second method. The maskinglayer 312 is disposed between the strain-limiting layer 102 and theinflatable layer 104, forming the channel 106. FIG. 3F is a photographof an actuator 318 fabricated in accordance with the second method.

The two methods illustrated in FIG. 3 are amenable to both easyprototyping and easy manufacturing. For example, for easy prototyping,different layers of the flexible actuator can be cut (i.e., shaped)using laser cutting techniques; for easy manufacturing, different layersof the flexible actuator can be cut using die cutting techniques thatare already prevalent in industrial settings. Photolithographictechniques or other expensive and time-consuming processes are notneeded.

The flexible robotic actuator can be designed to provide certain,sometimes complex, three-dimensional motions. For example, dependingupon the number and arrangement of the pressurized channels andmaterials selected for the strain-limiting and elastomeric sheet, thelaminated robotic actuator can perform bending, twisting, grabbing, andcurling motions. Robotic actuators can be designed that incorporate oneor more of these motions.

FIG. 4 illustrates a flexible, bending actuator in accordance with someembodiments. FIG. 4A shows the structure of the curling actuator 402.The curling actuator 402 includes a strain-limiting layer, an adhesivelayer, and an inflatable layer. The strain-limiting layer is a polyesterthin-film (i.e., PET) 50 micro-meters in thickness; the inflatable layeris a latex rubber sheet 150 micro-meters in thickness; and the adhesivelayer is a double sided tape with a thickness of about 50 micro-meters.The adhesive layer is patterned (or cutout) so that when the tapeadheres the strain-limiting layer to the inflatable layer, the interfacebetween the two layers forms a plurality of interconnected channels 406.The plurality of interconnected channels 406 are configured to receive apressurizing fluid via the fluid inlet 404. The fluid inlet 404 can bein fluid communication with a pressure source (not shown in the figure).

FIG. 4B shows the curling actuator 402 in its resting state, hangingfrom a clip. In its resting state, the curling actuator 402 is staticand conforms to the gravity. In contrast, FIG. 4C illustrates the samecurling actuator 402 in its pressurized state, pressurized with about 3ml of pressurized air. In its pressurized state, the curling actuator402 bends around the inflatable layer, working against gravity. Thepressure applied to the curling actuator 402 can be controlled so thatthe inflatable layer 104 for the curling actuator 402 does not expandupon pressurization.

FIG. 4D illustrate a curling actuator 402 lying horizontally at itsresting state, and FIG. 4E illustrate the same curling actuator 402lying horizontally at its pressurized state, pressurized with about 3 mlof pressurized air. At its pressurized state, the curling actuator 402curls around the inflatable layer, working against the gravity.

In some embodiments, a twisting motion of a thin actuator can be encodedinto the shape of the channel. FIGS. 5A-5B illustrate a twistinglaminated soft robot and its movement in accordance with someembodiments. FIG. 5A shows a channel embedded in a twisting thin softrobot 502. As illustrated in FIG. 5A, the twisting thin soft robot 502can include a channel shaped as a tree, having a central flow conduit504 with slanted branches 506. The angle of the slanted branches 506with respect to a central axis of the robot can determine the motion ofthe thin soft robot as it receives pressurized air via a gas inlet 508.For the thin robot 502, the central axis is aligned with the a centralflow conduit 504 of the channel. When the branches 506 are disposed atequi-angles, e.g., at a right angle with the central axis, then as theactuator receives pressurized air, the laminated actuator curls at rightangles with the central flow conduit 504 of the channel, as illustratedin FIG. 4C. However, if the slanted branches 506 are at less than aright angle with the central axis, (e.g., the smaller of the angles 510a and 510 b between the slanted branches 506 and the central axis is anacute angle), then as the actuator receives pressurized air, the thinactuator would twist, as illustrated in FIG. 5B, because the actuatorcurls at an acute angle with respect to the central axis.

As the angle between the central axis and the slanted branches 506becomes smaller, e.g., more acute, the thin actuator twists at a sharperangle (the actuator twists faster as a function of input pressure.) Forexample, if the input pressure is 2 psi, an actuator having slantedbranches 506 at 60 degrees with the central axis would twist morecompared to an actuator having slanted branches 506 at 80 degrees withthe central axis pressurized to 2 psi.

In some embodiments, the orientation in which the thin actuator curlsdepends on which of the two angles 510 a and 510 b is smaller. Forexample, if the angle 510 a is smaller than the angle 510 b, then theactuator 502 would twist in a counter-clockwise direction, asillustrated in FIG. 5B. However, if the angle 510 a is larger than theangle 510 b, then the actuator 502 would twist in a clockwise direction.

In some embodiments, a single channel can encode different types ofmotions. For example, a top portion of a channel can include slantedbranches at a right angle with respect to the central axis, which wouldinduce a curling motion at right angles to the central axis. However, alower portion of the channel can include slanted branches at 45 degreeswith the central axis, which would induce a twisting motion. Therefore,different parts of the actuator can be encoded with different motionsusing different channel structures.

In some embodiments, a channel can be arranged in a radial manner toencode a radial curling motion in thin soft robots. FIGS. 6A-6Billustrate a radially curling thin soft robot and its movement inaccordance with some embodiments. FIG. 6A shows a channel embedded in aradially curling thin soft robot 602. As illustrated in FIG. 6A, thetwisting thin soft robot 602 can include a channel shaped as a treearranged in a radial manner, having a curved central axis 604 with pieshaped branches 606, e.g., the channels or “branches” are larger on theoutside of the curved line defined by the curved central axis and taperto a smaller size on the inside of the curved line defined by the curvedcentral axis. The arrangements of the pie shaped branches 606 withrespect to the shape of the robot 602 determines the motion of the thinsoft robot 602 as it receives pressurized air via a gas inlet 608, asillustrated in FIG. 6B.

FIGS. 7A-7B illustrate a lifting thin robot that is configured to liftthe center portion of the actuator in accordance with some embodiments.The ability to elevate the center portion of the flat soft roboticallows object placed on the robotic to be raised or elevated. FIG. 7Ashows a channel structure associated with the lifting thin robot. Thelifting thin robot 702 can include radial channels 704 arranged in aconcentric manner about a central point, and connecting channels 706perpendicular to the radial channels 704. Upon pressurization, theradial channels 704 deflect away from the surface of the strain-limitinglayer. When the soft robotic is positioned so that the strain-limitinglayer faces upward, actuation causes the elastic layer to deflectdownward into the plane of the underlying supporting surface, therebyelevating the central section 708. Cross channels 706 can providemechanical support for the soft robot during actuation. FIG. 7B shows alifting motion of the lifting thin robot 702 as the pressure levelincreases. In this example, the mass of the cup is 12.1 grams.

In some embodiments, a thin soft robot can be reinforced to strengthenthe limbs of the laminated actuator and to provide additional physicalsupport. FIGS. 8A-8B show a thin actuator strengthened with reinforcingbeams in accordance with some embodiments. As shown in FIG. 8A, the thinactuator 802 includes a pneumatic channel 804 for providing actuationand one or more reinforcing structures 806. Upon pressurization, thepneumatic channels 804 induce bending motion, as discussed in FIG. 4C.The reinforcing structures 806 provide an additional strength to theactuator 802. The reinforcing structures 806 can be particularly usefulwhen the inflatable layer and the strain-limiting layer do not havesufficient mechanical strength to support the entire structure, or whenthe pneumatic channels 804 do not encompass the entire thin actuator 802and the actuation force is then transferred along the length of theactuator. The support structure can include arches, beams, or columnsformed using stiff materials, including wood, metals, plastic or a tape.FIG. 8B shows the movement of the thin robot 802 upon pressurization.The thin robot 802 may only curl in regions with the pneumatic channels804; the rest of the thin robot 802 made rigid by the reinforcingstructures 806. As reinforced, the ‘legs’ of the actuator are able tosupport the mass of the thin robot 802.

Flexible robotic actuators can be designed to be capable of complexmotions. FIG. 9 illustrates a flexible, locomoting actuator capable ofan undulating motion that allows the device to move across a surface inaccordance with some embodiments. The locomoting actuator 902 caninclude a curling actuator, substantially as illustrated in FIG. 4C. Thestrain-limiting layer of the curling actuator can include a duct tapeand/or a strip of transparency tape, and the inflatable layer of thecurling actuator can include a latex rubber and/or paper. The adhesivelayer can be shaped to provide a plurality of interconnected channels,as in the curling actuator 402 of FIG. 4A. The bottom surface of theundulating actuator 902 further includes walking pads 904, 906. Thewalking pads 904, 906 were cutout from a brush for removing lint. Thewalking pads 904, 906 include asymmetrically aligned bristles that arealigned to lie flat against the pad surface when moved in one directionso that movement occurs freely and to engage the underlying surface andresist movement when moved in the opposite direction. The actuator isperiodically pressurized, initiating the bending motion. However,because of the walking pads, walking pad 906 remains anchored on thesurface and walking pad 904 curls up to it. As pressure is released andthe actuator unbends, walking pad 904 now remains anchored to theunderlying surface and walking pad 906 slides forward to unbend theactuator. By cyclically actuating and releasing the device, the actuatormoves in a predetermined direction (i.e., left to right).

In some embodiments, a robot can perform complex motions when its thinactuators are provided with appropriate instructions. For example, oneor more of its thin actuators can be actuated independently to providedesired complex motions. FIGS. 10A-10E illustrate a robot having aplurality of thin actuators in accordance with some embodiments. Therobot has three bending actuators stacked over each other. Each curlingactuator in the robot has a strain-limiting layer, an inflatable layer,and an adhesive layer. The strain-limiting layer can include a ducttape, and the inflatable layer can include a latex rubber and/or paper.The adhesive layer can be shaped to provide a plurality ofinterconnected channels 406, as in the curling actuator 402 of FIG. 4A.

Each of the bending actuators in the robot can receive different motioninstructions. For example, each of the bending actuators can beindependently pressured at different pressures at different times to becontrolled independently. For instance, in FIG. 10A, all the bendingactuators are in their resting state. In FIG. 10B, the top bendingactuator is pressurized, providing a curling motion; in FIG. 10C, boththe top bending actuator and the middle bending actuator arepressurized, thereby providing a curling motion to both the top bendingactuator and the middle bending actuator; in FIG. 10D, all the bendingactuators are pressurized, providing a curling motion to all theactuators; and in FIG. 10E, all the bending actuators are depressurized,so all the bending actuators return to their resting states.

A plurality of thin robot actuators can be assembled into a single robotto provide a robot capable of complex motions. FIGS. 11A-11D illustratea flexible gripper device having three bending actuators in accordancewith some embodiments. The gripper of FIG. 11 has three bendingactuators, each bending actuator having a strain-limiting layer, aninflatable layer, and an adhesive layer. The bending actuators in thegripper can be designed to satisfy certain mechanical characteristics,such as the strength of the grip upon actuation. The strain-limitinglayer can include a duct tape and/or a strip of transparency, and theinflatable layer can include a latex rubber and/or paper. The adhesivelayer can be shaped to provide a plurality of interconnected channels406, as in the curling actuator 402 of FIG. 4A.

FIG. 11A shows the gripper suspended by at least one silicone tubing influid communication with one or more bending actuators. The silicontubing can be configured to provide fluid to one or more curlingactuators in the gripper. In some embodiments, each silicon tubing canbe coupled to one bending actuator, thereby providing independentcontrol of the bending actuators in the gripper. In other embodiments,silicone tubings can be coupled to all bending actuators, therebyproviding higher pressure to the curling actuators. FIG. 11B shows theunderside of the gripper in accordance with some embodiments. Thegripper can include a triangular piece of acrylic at the center. Thetriangular piece of acrylic can be configured to provide fluid to allthe bending actuators using a single fluid inlet coupled to the pressuresource. FIGS. 11C-11D illustrate the operation of the gripper. In FIG.11C, the gripper picks up a Styrofoam cup; in FIG. 11D, the gripperpicks up a paper cup. In both of these cases, the grippers werepneumatically pressurized at approximately 34 kPa (5 psi).

In some embodiments, the gripper can be operated to perform a walkingmotion. For example, one or more of the actuators in the gripper can beactuated independently or in concert to mimic a walking motion. In someembodiments, the gripper can perform its walking motion to move to alocation proximate to an object of interest, and subsequently use itsactuators to grab the object of interest.

FIG. 12 shows a soft robot capable of supporting itself in accordancewith some embodiments. The self-supporting robot 1202 can include two ormore thin actuators 1204 capable of providing a physical support. Theself-supporting robot 1202 can support an object at a raised positionwhen its thin actuators 504 receive pressurized air. The thin actuators1204 can include a bending robot 402 and/or a partially bending robot802.

FIG. 13 illustrates an expanding robot that provides an expandingmovement in accordance with some embodiments. The expanding robot caninclude two or more thin actuators 1302 stacked on top of one another,but are arranged to physically repel one another upon actuation, asillustrated in FIG. 13. To ensure that the thin actuators 1302 stay asone piece even upon actuation, the thin actuators 1302 can be adhered toone another. In some embodiments, the thin actuators 1302 are adhered toone another using an adhesive tape 1304. The thin actuators 1302 caninclude a bending robot 402 and/or a partially bending robot 802. Insome cases, the expanding robot 1302 can be useful for separating twoobjects for a desired period of time. For example, during a surgicaloperation, the expanding robot 1302 can separate two organs for adesired period of time to provide a line of sight for surgeons. Inanother example, the expanding robot 1302 can provide a jumping motionwhen it receives a pulse of pressurized air.

In some embodiments, a robot can include one or more of its actuatorsthat are preconfigured to perform a predetermined task. FIG. 14illustrates a robot having one or more actuators configured to perform apredetermined task in accordance with some embodiments. This robotincludes four actuators: pulling actuators 1402 are configured topulling the robot vertically and grabbing actuators 1404 are configuredto grabbing an object. The actuators 1402 and 1404 can be physicallycoupled to one another using, for example, a tape. Based on motioninstructions, each of these actuators can be actuated independently orin concert with one another. In the top figure, the grabbing actuators1404 are placed over a cup, and in the middle figure, the grabbingactuators 1404 grabs the cup. Then in the bottom figure, the grabbingactuators 1404 are raised using the pulling actuators 1402.

In some embodiments, a robot can include a plurality of channels, andone or more of the channels can be pressurized independently to actuatedifferent parts of the robot. FIGS. 15A-15B illustrate an actuator witha plurality of channels in accordance with some embodiments. FIG. 15Ashows the channel structure in the actuator. The actuator has fourchannels 1502, 1504, 1506, and 1508. The two channels 1502 and 1504 formthe pneumatic channel for controlling the body of the actuator, and theremaining two channels 1506 and 1508 form the pneumatic channel forcontrolling the limbs of the actuator. FIG. 15B illustrates the motionof the actuator for a certain motion instruction. At a rest position,the actuator's limb is placed below a pen. Subsequently, the pneumaticchannel in each limb 1506 and 1508 can be independently pressurized tograb the pen, and the body channels 1502 and 1504 can be pressurized tohold and lift the pen. The actuator weighs 13.5 g and is about 0.35 mmthick. This particular implementation of the actuator can lift objectsup to 10 g in weight. However, the strength of the actuator can becontrolled by using different materials for the inflatable layer and thestrain-limiting layer, and also by using highly pressurized gas topressurize the pneumatic channels.

FIGS. 16 and 17 illustrate another robot with a plurality of thinactuators in accordance with some embodiments. The illustrated robot isa glider having three parts: a body, a wing, and a nose. FIGS. 16A-16Cillustrate the channel structure for the body, the wing, and the nose,respectively. The channels for the body are configured to roll the bodypart into a cylinder; the channels for the wing are configured toactuate the wing into an airfoil shape; and the channels for the nose isconfigured to form a cone that caps one end of the rolled body. FIG. 17Aillustrates the body 1702, the wing 1704, and the nose 1706 for theglider. The wing 1704 is attached to the body 1702 by physically weavinga portion of the wing 1704 onto the body 1702. FIG. 17B-17D illustratethe motion of the robot. In FIG. 17B, the body 1702 of the glider isrolled up to form a cylinder; in FIG. 17C, the wing 1704 is actuated toform an airfoil shape; and in FIG. 17D, the nose is actuated to form acone that caps one of the rolled body. This implementation of the gliderweighs about 22.6 g and is about 0.35 mm thick. In some embodiments, theglider structure can be used as an ultra-light aircraft, a waterstrider, or any other robots that may advantageously leverage the lightweight characteristics of the thin actuators.

The thin actuators can provide new mechanisms for controllingaerodynamic characteristics of an object. FIG. 18 illustrates howflexible actuators provide control of an aerodynamic structure inaccordance with some embodiments. FIG. 18A illustrates a rotor 1802having a body and a plurality of flexible actuators 1804, where the bodyand the flexible actuators 1804 are formed using papers. The rotor 1802is designed so that when dropped, the rotor 1802 would spiral downward.

To understand the effect of flexible actuators 1804, the rotor 1802 wasdropped multiple times from a fixed position, with and without theactuators pressurized, and the aerodynamic properties of the rotor 1802were characterized. The characterized aerodynamic properties include thedrop time (i.e., the time it takes for a rotor to reach the ground whendropped from a fixed position) and the motion trajectory (i.e., thetrajectory of a rotor when dropped from a fixed position.)

FIG. 18B shows the drop time of the rotor 1802, with and withoutpressurized actuators 1804. FIG. 18B illustrates that the rotor 1802takes a longer time to reach the ground when its actuators 1804 arepressurized. This result illustrates that the actuators 1804 in therotor 1802 can affect the drag (i.e., fluid resistance) of the rotor1802. The motion trajectory of a rotor 1802 is indirectly characterizedby observing the location at which the rotor hits the ground whendropped from a fixed position. FIG. 18C shows the drop location ofrotors 1802 when their actuators 1804 are pressurized, and FIG. 18Dshows the drop location of rotors 1802 when their actuators 1804 are notpressurized. These figures illustrate that the drop locations of rotorswith pressurized actuators are consistent, whereas the drop locations ofrotors with unpressurized actuators are highly varying. This serves asan evidence that the pressurized actuators 1804 can provide a control ofmotion trajectory. Therefore, these experiments illustrate that flexiblerobotic actuators can provide advanced mechanisms for controlling theaerodynamic properties of an object.

The flexible robotic actuator can be used in a variety of otherapplications. For example, the curling actuator of FIG. 4 can be used toprovide a bending sheet. Also, the undulating actuator of FIG. 9 can beextended to provide an undulating motion on a surface of liquid such aswater. Additionally, a flexible actuator can be used to form an acousticmedium of varying acoustic characteristics. For example, a portion of awall can be formed using a flexible, pressurizable actuator. When theflexible actuator is at its resting state, the wall would exhibitcertain sound transmission characteristics; when the flexible actuatoris at its pressurized state, the wall would exhibit different soundtransmission characteristics. By controlling the material propertiesand/or physical geometry of the flexible actuator, the wall's soundtransmission characteristics can be controlled.

In some embodiments, the flexible robotic actuators can be powered usingan off-board pressure source. The pressure source can include acompressed air source connected to the actuators through flexibletubing. The flexible tubing can include a silicon tubing. The flexibletubing can be meters long without loss of performance. In otherembodiments, the flexible actuators can be powered by using an on-boardpressure source. The on-board pressure source includes disposablecompressed air cylinders or an on-board pump configured to provide fluidsuch as gas, fluid, or oil. The on-board pump can include an on-boardmechanical air compressor, an on-board water electrolyzer, and anon-board chemical pump, as disclosed in the PCT Patent Application No.PCT/US11/61720, titled “Soft robotic actuators” by Shepherd et al.,filed on Nov. 21, 2011.

In some embodiments, the pressure source coupled to the flexible roboticactuator can be controlled using software running on a computationaldevice. The software needed for implementing the control processincludes a high level procedural or an object-orientated language suchas MATLAB®, C, C++, C#, Java, or Perl. The software may also beimplemented in assembly language if desired. In some embodiments, thesoftware is stored on a storage medium or device such as read-onlymemory (ROM), programmable-read-only memory (PROM), electricallyerasable programmable-read-only memory (EEPROM), flash memory, or amagnetic disk that is readable by a general or specialpurpose-processing unit to perform the processes described in thisdocument. The processors can include any microprocessor (single ormultiple core), system on chip (SoC), microcontroller, digital signalprocessor (DSP), graphics processing unit (GPU), or any other integratedcircuit capable of processing instructions such as an x86microprocessor.

Although the present disclosure has been described and illustrated inthe foregoing example embodiments, it is understood that the presentdisclosure has been made only by way of example, and that numerouschanges in the details of implementation of the disclosure may be madewithout departing from the spirit and scope of the disclosure, which islimited only by the claims which follow. Other embodiments are withinthe following claims.

The invention claimed is:
 1. A laminated robotic actuator comprising: astrain-limiting layer comprising a flexible, non-extensible material ina form of a sheet or thin film; a sealing layer comprising a flexible,non-extensible material in a form of a thin film or sheet in a facingrelationship with the strain-limiting layer, wherein a stiffness of thestrain-limiting layer is greater than a stiffness of the sealing layer,wherein the sealing layer is selectively adhered to the strain-limitinglayer, and wherein a portion of an un-adhered region between thestrain-limiting layer and the sealing layer defines a pressurizablechannel; and at least one fluid inlet, in fluid communication with thepressurizable channel, configured to receive pressurized fluid to causethe actuator to bend toward the sealing layer.
 2. The laminated roboticactuator of claim 1, further comprising an adhesive layer disposedbetween the strain-limiting layer and the sealing layer, wherein theadhesive layer is shaped to selectively adhere the sealing layer to thestrain-limiting layer to define the channel.
 3. The laminated roboticactuator of claim 1, wherein one of the strain-limiting layer and thesealing layer is coated with an adhesive, and further comprising amasking layer disposed between the strain-limiting layer and the sealinglayer, wherein the masking layer defines a shape of the un-adheredregion between the strain-limiting layer and the sealing layer.
 4. Thelaminated robotic actuator of claim 1, wherein the strain-limiting layercomprises the adhesive coating.
 5. The laminated robotic actuator ofclaim 1, wherein the channel comprises a plurality of interconnectedchambers configured to provide a twisting motion of the laminatedrobotic actuator upon pressurization of the channel via the fluid inlet.6. The laminated robotic actuator of claim 1, wherein the channelcomprises a plurality of interconnected chambers configured to provide abending motion of the laminated robotic actuator upon pressurization ofthe channel via the fluid inlet.
 7. The laminated robotic actuator ofclaim 1, wherein a stiffness of the strain-limiting layer is configuredto determine a physical strength associated with the laminated roboticactuator upon pressurization of the channel via the fluid inlet.
 8. Thelaminated robotic actuator of claim 1, wherein the channel comprises aplurality of interconnected chambers configured to provide two differentmotions of the laminated robotic actuator upon pressurization of thechannel via the fluid inlet.
 9. The laminated robotic actuator of claim1, further comprising a reinforcing structure for providing additionalphysical support to the laminated robotic actuator.
 10. The laminatedrobotic actuator of claim 1, further wherein the channel comprises aplurality of sub-channels that are independently coupled to the at leastone fluid inlet, thereby enabling independent pressurization of thesub-channels.
 11. The laminated robotic actuator of claim 1, wherein thechannel comprises a plurality of interconnected chambers arranged alonga curved central flow conduit.
 12. A twisting actuator comprising alaminated robotic actuator of claim 1, wherein the pressurizable channelcomprises a central flow conduit and a plurality of slanted branches,and the slanted branches are at an acute angle with respect to a centralaxis of the actuator to determine a twisting motion of the actuator. 13.The twisting actuator of claim 12, wherein the central axis is alignedwith the central flow conduit.
 14. A lifting robot comprising alaminated robotic actuator of claim 1, wherein the pressurizable channelcomprises radial channels arranged in a concentric manner about acentral point of the laminated robotic actuator, and connecting channelsperpendicular to the radial channels, wherein the radial channels areconfigured to deflect away from a surface of the strain-limiting layerupon pressurization.
 15. A robot comprising a plurality of actuatablearms, wherein one of the plurality of actuatable arms includes alaminated robotic actuator of claim
 1. 16. The robot of claim 15,wherein the robot comprises 2, 3, 4, 5, 6, 7, 8 or more actuatable arms.17. The robot of claim 15, wherein one or more of the plurality ofactuatable arms is configured to be actuated independently.
 18. Agripping device comprising a plurality of actuatable arms, wherein eachof the plurality of actuatable arms includes a laminated roboticactuator of claim 1, wherein the plurality of actuatable arms areconfigured to bend from a first resting position to a second actuatedposition upon pressurization.
 19. The gripping device of claim 18,wherein the gripping device comprises 2, 3, 4, 5, 6, 7, 8 or moreactuatable arms.
 20. The gripping device of claim 18, wherein one ormore of the plurality of actuatable arms is configured to be actuatedindependently.
 21. A method for providing a flexible robotic actuator,comprising: providing a strain-limiting layer having a substantiallytwo-dimensional layer of a first flexible material, wherein thestrain-limiting layer is non-extensible; providing a sealing layerhaving a substantially two-dimensional layer of a second flexiblematerial, wherein the sealing layer is non-extensible, and thestrain-limiting layer is stiffer compared to the sealing layer;determining a shape of a region at which the sealing layer is to beadhered to the strain-limiting layer; and adhering the sealing layer tothe strain-limiting layer based on the shape of the region, therebyforming a channel for fluid communication having the shape that, uponreceiving pressurized fluid, causes the actuator to bend towards thesealing layer.
 22. The method of claim 21, further comprising providingan adhesive layer between the strain-limiting layer and the sealinglayer, wherein the adhesive layer is shaped to selectively adhere thesealing layer to the strain-limiting layer to define the channel. 23.The method of claim 21, further comprising providing a masking layerdisposed between the strain-limiting layer and the sealing layer,wherein the masking layer defines a shape of the un-adhered regionbetween the strain-limiting layer and the sealing layer.
 24. A method ofactuating a laminated soft robotic comprising: providing a laminatedsoft robotic according to claim 1; and initiating a series ofpressurizations and depressurizations that actuate the laminated softrobotic to provide a predetermined motion.
 25. The method of claim 24,wherein the series of pressurization and depressurizations provide asequence of two or more predetermined motions.
 26. A method of grippingcomprising: providing a plurality of laminated robotic actuatorsaccording to claim 1; and initiating a series of pressurizations anddepressurizations that bring the actuators in gripping contact with atarget object.
 27. The method of claim 26, further comprising initiatinga series pressurizations and depressurizations to perform a walkingmotion.
 28. The method of claim 24, wherein the pressure of the fluidapplied to the channel via the fluid inlet is selected to provide apredetermined range of a motion.